With the advent of the cellular telephone communications systems, the portable communications industry has experienced tremendous growth. It is estimated that there are presently over 20 million Americans who own and operate a cellular telephone. In addition, there are several million Americans who have applied for service with a cellular telephone carrier, but have been denied service because of insufficient or a bad credit history. As a result, a significant segment of the potential market for the cellular telephone industry is excluded from receiving or even being considered for cellular telephone service.
The prior art discloses various techniques for operating a communication system base site to accept or deny a request for access from a communication unit. For example, U.S. Pat. No. 5,274,368 to Breeden et al., assigned to Motorola, Inc., discloses such a system where a communication base site processes predetermined identification codes to determine whether a particular request for access to the base site is authorized. U.S. Pat. No. 4,908,848 to Hanawa discloses another technique for operating the mobile communication system to restrict certain types of call operations. Again, the system proposed by Hanawa, like the Breeden et al. system, requires modification of the communication system base site to recognize particular unique codes associated with a request for service from a particular portable communication unit. The modifications suggested by such prior art systems, however, have not been widely nor consistently implemented.
Theft of portable communication service, particularly with respect to cellular telephone service, has been increasing at an alarming rate and now represents a major problem in the industry. In some cases, the portable communication service user is placed in an awkward position where hundreds or even thousands of dollars of unauthorized communication service has been charged to the account of the user. If the user is able to establish that such service was unauthorized, the portable communication service provider will lose the revenue for the service provided that was unauthorized. In addition to theft of service, theft of portable communication equipment has also been increasing. Portable communication equipment, which may not be recognized as stolen until significant unauthorized service has been used, is very costly to the user and the service provider.